It creates a division in his mind between the woman he knows to be his natural mother and the woman with whom he has real hands-on relationship: the woman who bathes him and takes him to the park, and with whom he feels completely at one.
As a result, he grows up with the idea that although he will one day go through all the social and sexual formalities of marriage, he will have at the back of his mind the notion of this other woman, who not only knows, but caters for, all his needs.
And yet apparently, according to Dr. Friedman, all of this can be avoided merely by not hiring a nanny until after the baby's first year.
Is this all too Freudian to believe? Or, in hiring a nanny, have mothers everywhere ruined their daughters-in-law's lives before even meeting them?